#include <stdlib.h>
#include <stdio.h>
#include <GL/freeglut.h>

void display()
{
	glClear(GL_COLOR_BUFFER_BIT);
	glColor3f(1.0, 1.0, 0.0);
	glBegin(GL_LINES);
		glVertex3f(0.25, 0.25, 0.0);
		glVertex3f(0.75, 0.25, 0.0);
		glVertex3f(0.75, 0.75, 0.0);
		glVertex3f(0.25, 0.75, 0.0);
	glEnd();

	glFlush();
}

void init()
{
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrtho(0.0, 1.0, 0.0, 1.0, -1.0, 1.0);
}

int main(int argc, char* argv[])
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
	glutInitWindowSize(600, 600);
	glutInitWindowPosition(100, 100);
	glutCreateWindow("hello");
	init();
	glutDisplayFunc(display);
	glutMainLoop();
	return 0;
}
